The next wind tunnel session- suggestions

[Guest TeamNissan]

I dont want to get ahead of anything but from the turn out, FANTASTIC results, support and the great admins and members here that there will be (eventualy) another wind tunnel session to further test certain ideas. I and I know a bunsh of other fellow members have alot of ideas to try and fit into the next session, if they are worthy and time permiting ofcourse. I was going to bring it up in another thread and I noticed a admin suggest another thread just for the topic so here we are.

 

Right off the bat I would love to see some rear diffuser testing. Just bottom rear testing in general would be really great. I'm afraid the lower rear valance acts like a parachute at speed esp when smoothed over and not stock. I have seen quite a few old datsun racing pics where they completely blocked off the area and added a diffuser and I can only asume thats why.

 

Also I know alot of people (on other cars) raise a lip on the back end of thier hood to block the wipers and make a smoothers transition to the windshield to lower the coefficient. We I think could quite easily do that. I know the guy in the netherlands who chopped the top on his 240z (dont think he is a member here)did it but I dont think there was any testing done.

 

Those are some ideas but not my only, I'd like to see some other people chime in befor I go on and on.

[proxlamus©]

Look back on the results thread.. the rear diffuser and underbody enhancements were considered a waste of time, when there is so much to modify on the body of the car.

 

As Mike emphasized time and time again, the total package and combination of aerodynamic mods were the key to improving the Z's aerodynamics.

[Guest TeamNissan]

Ya a waste of time when there is so much already to be tested i.e. spoilers, air dams and what not but eventualy it should be tested. Its not like most of us dont hack our cars up for this or that anyway.

 

Yes mike did emphasize that and I believe it holds true FOR THAT SESSION.

We can only draw conclusions from what was and will be tested. Why go through all this trouble and the admins so much work just to go and asume certain things are and are not a waste of time? I believe it was passed on because the plate was already full not that there werent gains to be had.

[JMortensen]

The wind tunnel operator thought the rear diffuser was a waste of time, not Mike Kelly. It was stated that bigger gains could be had working on the top of the car than the bottom.

 

Here's a list of things that I would like to see in the next test. I don't expect that this will all happen, but these are suggestions:

 

1. The car lower to the ground

2. The airdam much lower to the ground, maybe 2" from ground level or so

3. Sealed and sloped airbox from the airdam to the core support

4. Bigger vents in hood, with a trip strip in front of the vents

5. Large single plane wing on back, with and without Gurney flap

6. Test with splitter vs without to see the difference the lip makes

7. Test with window nets, both the "strap style" and the fine mesh style

8. Flare/airdam combo which covers the leading edge of front and rear tires and preferrably sticks out at least 2 or 3 inches past the tires on each side

9. Holes in bottom of rear window

10 Holes in top of rear window

[OlderThanMe]

I think that by the time you get the car low enough to use a diffuser then it won't be anywhere near a stretable car. Most of the Zs tested seemed had average ground clearance of more than 4"...

Most race cars that use them [diffusers] have less than 2" of clearance...

Just a thought...

[74Adam]

I have a question. Is this facility able to do smoke trails (sorry, don't know the correct term.)?

[Mikelly]

My recommendation (And what I'll do when I take my car there) would be to do pressure tests and smoke trails.

 

This means we won'd be swapping a bunch of parts. The time it takes to set up the pressure tubes inbetween tests could eat up as much as an hour between sessions. What this also means is less data collected, but likely more finite data that would resolve issues like sealing off the radiator core support, and measuring under hood pressures.

 

And yes, Bob Smith said rear difusers are a waste of time. Here's why I personally agree with him:

 

On both my C5 Corvette, AND on my 996TT, the bottom of both cars is flat as a sheet of plywood. We don't have that with out Zcars. Further, cleaning up the underside of the car might impact a number of areas negatively. Impacting that is the simple fact that our Zcars have a lot of sharp and abrupt edges. Unless you completely redid the whole underside of the car, and then worked dogedly to do a widebody kit (Like Bob_H's) and covered all the other issues, doing a rear difuser would be a complete waste of time. We're dealing with 35 year old cars, and we're also trying to get the biggest bang for the buck in testing for ALL of our members.

 

I suspect a sub-set of racers will probably go into the tunnel next to test things specific to their personal applications. Maybe you, Teamnissan could get on that band wagon and chip in for some rear difuser testing? You want to whip up a few ideas and make them for use in testing?

 

Mike

[Guest TeamNissan]

Makes sense to me, esp bang for buck. I didnt realize that the wind tunnel guy was the one who said it was a waste of time as J stated. I didnt think any of you guys did either, I figured there was just too much to do already.

 

I'll be the 1st to admit I'm a dreamer and maybe some of my idea are far fetched. I would def be up for taking a drive down for the next session in a second, if I'm invited I'm there, diffused z and all . I'd also try sealing the entire undercarriage and the lip for the wipers. If the trip was to be taken I'm sure I could incorporate some other fellow hybrider ideas too, mite as well.

 

I REALLY like j's ideas #2 and #4 too.

[Mikelly]

Uh, I don't think you understand. This wouldn't be a "donations" deal. This would be a "Pony up your 1/4 of the $3500 or more" kinda deal.

 

Any donations driven testing would be hammered out by the admin staff and those doing the donating. I can also state that, it was expensive enough on all those who took time out of work and life to shack up in hotel rooms and gas getting cars to and from (All the cars had to be towed in from out of town) that the next effort with donations will likely be closer to $5000. It's simply to expensive on the players NOT to at least cover their expenses for gas/hotels/food, unless they wave that off.

 

Mike

[Synlubes]

Any donations driven testing would be hammered out by the admin staff and those doing the donating. I can also state that, it was expensive enough on all those who took time out of work and life to shack up in hotel rooms and gas getting cars to and from (All the cars had to be towed in from out of town) that the next effort with donations will likely be closer to $5000. It's simply to expensive on the players NOT to at least cover their expenses for gas/hotels/food, unless they wave that off.

 

Mike

 

I will gladly donate additional monies to help cover/offset some of the costs of those that participated in the first round if you want to set that up.

[Guest TeamNissan]

Ya Me either too be honest, w/e is needed. If I'm not welcome with the hybridz crew or you guys dont need/want my help I would be just as happy shacking up with a 3rd party. How ever it works out I would be happy to be involved, for us all.

[Guest TeamNissan]

Also after just talking with mike Mirrors popped into my mind... testing dif mirrors could be quick and effect drag.

[OlderThanMe]

How about having a suspension that you can adjust for ride height from inside the control room via remote?

 

I am thinking: remove all coil springs and attach a large threaded rod next to the strut with a motor attached with a worm gear so that you can raise and lower the car in the control room. That way you can test different ride heights in one blow.

Just another idea...

[Mikelly]

Ya Me either too be honest, w/e is needed. If I'm not welcome with the hybridz crew or you guys dont need/want my help I would be just as happy shacking up with a 3rd party. How ever it works out I would be happy to be involved, for us all.

 

Actually I was trying to explain that the next round may be a couple privateers pooling their funds. You may want to get in on that effort if you can afford to. My point was the total sum of users who donated would drive what we test next.

 

It wasn't meant as a "you're not welcome". It was meant as a "Let's look at maximizing the time avaliable". And based on the advice from the expert on hand, a rear difuser would go against that.

 

Also, in regards to mirrors, the Gnose equipped car didn't have mirrors or door handles, slicking the profile even more. I don't think it had vent emblems or an antenna either.

 

Mike

[cygnusx1]

Test Suggestions:

 

Where is all the air coming from that pushes up on the hood? Using no hood or fender vents:

a) completely block the nose/grill.

seal the air dam right down to the floor.

c) run rubber fins along the bottom of the front framerails to seal them close to the ground. (keep "wheel-well" air from going into the engine bay).

d) open a 4"h x 10"w hole in the grill.

e) unseal the airdam from the ground.

[LT280z]

How about having a suspension that you can adjust for ride height from inside the control room via remote?

 

I am thinking: remove all coil springs and attach a large threaded rod next to the strut with a motor attached with a worm gear so that you can raise and lower the car in the control room. That way you can test different ride heights in one blow.

Just another idea...

 

Air bags would be alot easier to construct....I have 4 firestone bags, tank, lines, brackets..If enough people want to to test ride heigth i can let someone use my set-up. It would actually be easy to install on the Z.

[capt_furious]

Stealing from another thread, it might be worth the effort to mock up the front setup from the early factory Works Zs.

 

 

[cygnusx1]

Test the cowl induction hood if possible. I have a brand new one hangining in my garage but shipping would be a real PITA.

[tkach]

Is their currently a timeframe for the next test session. If its later this year I hope to have a diffuser on my car ( I just love the look) and I also plan to incorprate many other aero mods that have been tested. However im just starting on these mods so ill need time. I'm trying to decied if i want a gt40/NSX style vented hood. The reason im still uncertian about such a mod is that it consumes a bit of my engine bay. Currently I have the space but I've got this urge to slap a turbo on the small block. I'm trying to put that urge to rest. I guess what im saying is id like to help out and Im stationed in South Carolina so im fairly close.

[Moridin]

Is their currently a timeframe for the next test session. If its later this year I hope to have a diffuser on my car ( I just love the look) and I also plan to incorprate many other aero mods that have been tested. However im just starting on these mods so ill need time. I'm trying to decied if i want a gt40/NSX style vented hood. The reason im still uncertian about such a mod is that it consumes a bit of my engine bay. Currently I have the space but I've got this urge to slap a turbo on the small block. I'm trying to put that urge to rest. I guess what im saying is id like to help out and Im stationed in South Carolina so im fairly close.

 

If you really want the rear diffuser to be much more effective, make a flat belly pan for the car. It would be cool to see the numbers for the difference it should make.